angularjs apply one class by ternary and another always

问题

I want to have the 'glyphicon' class on my icon tag always. I want to have the 'glyphicon-plus' class when item.expanded is false, 'glyphicon-minus' class when item.expanded is true.

It seems there would be a simple way to do this but I've been unsuccessful using the ternary operator when I need another class to always be there. The following code does not work.

<i ng-class="'glyphicon', (item.expanded) ? 'glyphicon-minus' : 'glyphicon-plus'"></i>

回答1:

ng-class don't really behave like this.

google says : What is the best way to conditionally apply a class?

so an answer for your question could be :

<i class="glyphicon" ng-class="{'glyphicon-minus' : item.expanded, 'glyphicon-plus' : !item.expanded}"></i>

来源：https://stackoverflow.com/questions/22940041/angularjs-apply-one-class-by-ternary-and-another-always